Are the symptoms only apparent when the bike is stone cold? Do the symptoms disappear when the engine warms up? If they do then it may possibly be the grease in the head race bearings stiffening up in the cold rather than the suspension fluids. Once the oil in the frame warms the headstock the grease will thin out. You can get low temperature grease for extreme climates, but I don't think they mean Belgium though! Maybe Siberia. Mate of mine changes all the grease on his pushbike in the winter for low temp stuff to make it easier to pedal and steer. Just a thought??

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